When I installed Duokan 2012 R1.1 Stable on my Kindle Keyboard 3G (GB) about a yer ago, I did a factory reset, thereby getting rid of the jailbreak that I had installed earlier.

Now, I would like to have the Jailbreak back, in order to use USB networking with the VNC viewer to make the Kindle a second screen to my laptop (potentially interesting in bright sunlight).

Is it possible to install the jailbreak in parallel to Duokan?

I tried the usual method of installing the jailbreak, copying the corresponding `bin` file to the root directory, then rebooting. However, that did not work. Upon loading, there was a message that the update failed. I know that a similar message shows up even when jailbreak installation succeeds, but then the Kindle automatically reboots, and in my case it didn't. Nevertheless, I tried installing USB networking, but - no surprise - I could not activate it afterwards. So the jailbreak most likely did not work.